Aromatic compound polymers such as polyarylene and the like are useful as functional materials such as fluorescent polymer materials, conductive polymer materials and the like, and as the methods for producing thereof, methods of oxidatively polymerizing an aromatic compound in the presence of a vanadium complex catalytic system and an oxidizing agent are known (Literatures 1 and 2).
[Literature 1] Journal of Electroanalytical Chemistry 1997, 438, 167
[Literature 2] Macromolecules 1996, 29, 7645
For example, Literature 1 discloses a method of polymerizing pyrrole by using a catalyst prepared from (N,N′-ethylenebis(salycylideneaminato))oxovanadium(IV) (VO(salen)) and an acid, as the catalyst, in the presence of oxygen.
The catalytic system used in the method of Literature 1, however, hardly promotes a polymerization reaction when being applied to polymerization of p-dialkoxybenzene.
Literature 2 discloses a method for producing a polymer wherein p-dialkoxybenzene is polymerized in the presence of oxygen, by using a catalyst prepared from vanadyl acetylacetonato (VO(acac)2) and an acid under co-presence of anhydrous trifluoroacetic acid as a dehydrating agent of which amount is 2 equivalent per p-dialkoxybenzene as the raw material.
This method has a problem that polymerization seldom proceeds without co-presence of a large amount of a dehydrating agent.
As mentioned above, the conventional methods occasionally result in very low yield of polymer depending on the kind of an aromatic compound as the raw material, and a large amount of a dehydrating agent is required to polymerize such raw material, accordingly, this case is not always preferable for industrial production because of purification of the intended polymer becomes difficult.